Endless raw edge v-belt



Aug. 17, 1965 J. ROCKOFF ETAL. 3,200,662

ENDLESS RM! EDGE V-BELT Original Filed March 13, 1958 2 Sheets-Sheet 1 JOSEPH ROCKOFF DALE L. WAUGH WALTER EHUBER INVENTORS ATTORNEY Aug. 17, 1965 J. ROCKOFF ETAL ENDLESS RA! EDGE V-BELT Original Fiied March 13, 1958 2 Sheets-Sheet 2 United States Patent Ofiice 3,2tlli,liii2 Patented Aug. 17, 1965 3,205,662 ENDLESS RAV EDGE V-BELT Joseph Rockotf, Dale L. Waugh, and Walter E. I-Iuber,

This application is a division of US. application Serial No. 721,169, filed March 13, 1958 (now Patent No. 2,991,498). This invention relates to power transmission belts of the type having substantially trapezoidal cross sections commonly referred to as V-belts. It relates in particular to V-belts known as raw edge.

The field of belt manufacture has been advanced to a point where high-quality, long-wearing products can be manufactured comparatively inexpensively. Large-scale manufacture of such belts, particularly V-belts, has led to their increasing use and increasing demands upon their capabilities. With these demands have come new developments, particularly in the field of strengtheningthe belt sections by means of new types of synthetic materials such as polyester fibers which are condensation polymers obtained from ethylene glycol and terephthalic acid, commonly known as Dacron, nylon, or other materials. Cords made of these fibers have been found to possess great advantages in strength, heat resistance and stretch resistance after an initial prestretch is put into these cords. As in all new products, however, new materials often create additional problems, and it is such problems and their solution which are dealt with in the present invention.

V-belts are made by numerous methods as, for example, those described in US. Patents No. 2,711,778, No. 2,726; 976 and No. 2,773,540, issued to Dale L. Waugh, one of the present co-inventors. By means of such processes a belt consisting of a trapezoidal cross section, commonly termed a V-belt, may be manufactured. Such a belt usually consists of an inner or compression section, an outer or tension section and a strength section located between the other sections, often referred to as a neutral axis portion. The neutral axis portion which actually carries the load during the operation of the V-belt com prises longitudinally extending cords embedded in cushioning layers. It is these cords which may be composed of the synthetic fibers. More specifically, a conventional belt method which results in the o-called raw edge belt such as illustrated in FIGURE of the last of the aboveenumerated patents, is made by spinning the cords longitudinally of the belt in a sleeve as described in the patents. The individual belts are then cutout of the sleeve with the result that some of the cords are skived and exposed along the sloping edges of the finished belt. This is necessarily true, of course, because the spinning operation causes the cords to be laid in a helical fashion while the cutting oporation is at right angles to the axis of the belt sleeve. It has. been found that operation of these belts in pulleys tends to cause the exposed fibers in the cords to ravel slightly. This condition becomes aggravated as the pulley seems to seize the short protruding fibers andtend to strip them from the cord. The condition continues to occur until a considerable amount of the cord has been removed along the edges with a resultant decrease in the strength of the belt as well as an appearance of deterioration.

It is, therefore, a principal object of the invention to provide a raw edge belt having sealed cord edges.

It is a further object of the invention to provide a belt with synthetic cords that are prevented from raveling where exposed on their edges.

These and other object will be apparent in the following specification and drawings, in which:

FIGURE 1 is a perspective view of the preferred form of the apparatus which is the subject of the present invention.

FIGURE 2 is a view partially in cross section showing a portion of the apparatus during operation.

FIGURE 3 is a cross-sectional view of a typical V- belt to be treated by the subject apparatus.

FIGURE 4 is a perspective view of a modification of a portion of the apparatus shown in FIGURE 1.

Referring now to FIGURE 1, the novel apparatus 11 consists of a bench-like structure composed of a pairof vertical legs 12 and 13, and a top 14 and shelf 15, both extending horizontally between the legs. the side of the top 14 is a bracket 16 which is attached by means of welding, bolting, or other conventional means. This bracket is of the right angle type and mounted on the horizontal portion thereof is a heater block 17. As

is best shown in FIGURE 2, the heater block 17 consists of a block of metal which is highly conductive and has a pair of strip heaters mounted on the sides thereof by means of screws or other conventional fastening devices 19. The block 17 has a slot in the center which has sides 20 tapered part way therein and are vertical the rest of the distance to form a rectangular opening 21. A thermostat tube 22 is mounted within the lower portion of the block in order to provide a thermostatic control for the heater. Referring again to FIGURE 1, a vertical bracket 23 is also mounted on the top and has a yoked configuration at its upper surface. A horizontally extending arm 24 is mounted in this yoke and is secured by means of pin type bearings 25. At one end of the arm 24 is mounted a bracket 26 which extends at right angles thereto. This bracket in turn has a pair of downwardly depending yoke arms 27 in each of which is mounted a rotatable pressure wheel 28 by means of bearings 29. At the opposite end of the arm 24 is another yoke 30 which is attached to the end of the arm by means of the bearing 31. Extending downwardly from the yoke is a shaft 32 which acts as a piston within the cylinder 33. This cylinder and piston are actuated by air pressure or hydraulic means (not shown) which are conventional and need not be described here. The operation of this portion of the device will be described later.

A bracket 34 is mounted on the upper portion of the leg 13 which extends above the top 14. On this bracket is mounted a bearing 36 carrying shaft which is freely rotatable therein. A pulley 37 is mounted on the shaft 35 by conventional fastening means, and is rotated by means of belt 38 which runs to another pulley 39 mounted on a motor 40. This motor is mounted on the shelf 15 as shown. The motor 40 includes a variable speed device in order to control the rotation of the pulley 37. Directly above the leg 12 is mounted another cylinder 41 in which is mounted a shaft or piston 42, actuated by hydraulic or pneumatic means from the same source as that which actuates cylinder 33. Mounted on the opposite end of the shaft or piston 42 is a bearing box 43 which is slidably mounted in the slot 48 of the top 14. A rotatable shaft 44 is mounted in the bearing box 43 and carries upon it a pulley 45.

Mounted on- 3 I The pulleys 37 and 45 are so aligned that a belt 46 upon which work is to be performed may freely pass around them while passing through the heater block '17.

Operation of the apparatus When a belt is to be finished, the cylinder 41 is actuated so that the bearing box 43 and pulley 45 are caused to move toward the opposite pulley 37. This provides sufficient slack so that the belt 46 to be treated may be placed around the pulleys. When this is done, the cylincicr 41 is again actuated in the opposite direction until the belt is taut, approximating its condition when used in its ultimate installation. As can best be seen in FIG- URE 2. the belt merely rides within the opening in the heater block 17 so that the sloping portions of the sides 20 are contiguous with the sloping sides of the belt, but are not in contact with the entire side area, due to the vertical configuration of the lower portion of the opening. The cylinder 33 is next actuated in such a fashion that the shaft 32 is extended upwardly thus causing the arm 24 to pivot about bearings 25 and lower the assembly consisting of bracket 26, yoke arms 27 and wheels 28. The actuation of the cylinder is stopped as soon as the wheels are in contact with the upper surface of the belt as shown in FIGURE 2, thereby causing an even contact to exist between the sloping sides of the belt and the heater block. The motor 40 is next actuated by conventional switch means, drawing its power from a conventional electrical source (not shown). This causes the pulley 39 to rotate and by means of belt 38 to drive the pulley 37. This in turn causes the belt 46 to travel around the pulleys and through the heater block. The strip heaters 18 are then actuated by a heating source (not shown), preferably electrical in nature and capable of providing a temperature of 600 to 700 degrees Fahrenhcit. The thermostat tube 22 maintains the desired tem perature. The belt is now operating at a speed of between one and two inches per second, preferably approximately one and one-half inches per second. The speed is fairly critical, as it has been found that speed which is too slow will cause the rubber or the cords 47 to be exposed to excessive heat. On the other hand, a speed greater than this will not provide proper exposureof the cords to the heat and will not permit the fibers to melt properly. It is believed that the success of the operation is due to the fact that the temperatures applied against the cords 47 are, as stated previously, in the range of 600 to 700 degrees Fahrenheit, which is well above the melt ing temperature of 480 degrees Fahrenheit for polyester fibers. The high tcmperture causes the short loose ends of the fibers to be melted off and also provides a partial fusion or weld between the exposed portion of the cord and the belt adjacent thereto. As a result of this operation, the frayed ends are thus removed and a smooth surface results, avoiding the previously described seizing of the cords.

Afterseveral rotations of the belt, the sealing has been properly effected, and the operator then actuates the cylinder 33 to permit the wheels 28 to rise, shuts off the motor 40 and again causes the pulley 45 to move inwardly toward the other pulley. This provides a, slack and the belt is then removed from the apparatus. The machine is now in position for the next belt upon whieh operation is to be performed and the previously described cycle is repeated.

Modification The above-described apparatus is capable of treating belts of any given cross section, and will provide satisfactory results where a large number of beltsof the same cross section are to be treated. Many manufacturers may provide a large variety of belt widths, angles, and heights, however, and it is also desirable to modify the machine to provide for any of these variations." Such a modification is illustrated in FIGURE 4 in-which an 4 adjustable heater block 50 is substituted for the heater block 17 of the principal form of the invention. All other'portions of the apparatus are identical. The heater block 50 instead of being unitary, is composed of two members 51 and 52. The member 51 has a pair of vertical brackets 53 and between these brackets is mounted an upper portion 54, having a shaft 55 integrally attached thereto and mounted on the bracket 53. Attached to the shaft 55 is a ratchet 56 and an indicator 57. A flexible stop 59 is mounted on the bracket 53 and a plurality of markings 58 are attached or stamped on the lower portion of the bracket 53 in such a fashion that the indicator 57 is adjacent thereto. As can be readily seen by examining FIGURE 4, the portion 54 of the heater is capable of rotation as the shaft passes through the brackct. As the shaft rotates so does the ratchet 56 and indicator 57 until it is held in position by means of the flexible stop 59. By means of the markings on the bracket it is possible to obtain a reference as to the position of the member. The member 54 is heated in similar fashion to the heater block of the principal form, although this hcatcr strip is not shown.

The other member 52 of the heater block has a structure which is identical to that of the member 51. This consists of a pair of vertical brackets 60, upper portion 61, shaft 62, ratchet 63, and indicator 64, all capable of rotation. The markings 65 and stop 66 perform the same function just described. The strip heaters 67, mounted by means of screws 68 or other conventional fastening members, are similar to the strip heaters 18 of the principal form.

The two members 51 and 52 are interconnected by means of a helically treated shaft 69 such as that commonly used for driving jaws of a vise. It is possible, therefore, by rotating the member 69 to actuate the members toward or away from each other similar to the action that occurs in a vise or in portions of a lathe. By combination of this transverse movement of the members and the rotation of the upper portions of the members, it is possible to obtain a contact with a V-bclt of almost any height, width, or included angle. The type of contact desired, of course, is similar to that shown in FIGURE 2 in which the cords of the belt are contiguous with the heated members. The device shown will easily accommodate belts having included angles between 25 and 40 degrees, which is sulficient to operate on entire low range of V-belts in common use. The pos t on shown in FIGURE 4 is midway of the extreme positions, and is, therefore, set at approximately 35 degrees.

When it is desired to utilize this adjustable heater block, the required lateral and angular adjustments are made and the remaining apparatus is operated exactly as described when referring to the principal modification.

It can thus be seen that by means of this invention a novelbelt'has been described having polyester or nylon strength cords. This belt can be finished by means of a novel apparatus consisting of a device which can selecttvely apply heat to these cords while the belt operates at such a speed that the exposed fibers of the cords are sealed without damaging the remainder of the belt. The operation occurs at asufficiently high speed to make this process extremely feasible and economical. The novel apparatus and method further enables an operator to finish belts of any desired length, width, height, or included angle with great dexterity and ease. The above form of the invention is purely exemplary and is not intended in any way to limit the invention. Other modifications within the spirit of the invention are contemplated.

We claim:

1. As an article of manufacture, an endless raw edge V-belt comprising compression, tension and neutral axis sections and longitudinally extending strength cords composed of synthetic fibersembedded in said neutral axis 5 section, the exposed fibers at the edges of said belt being 2,588,647 partially fused to the adjoining portion of the belt. 2,983,304 2. The article of claim 1 in which said fibers are poly- 3,090,716 ester.

3. The article of claim 1 in which said fibers are nylon. 5

References Cited by the Examiner UNITED STATES PATENTS 2,446,310 8/48 Steinke 15452.2

6 3/52 Mitchell 1544 XR 5/61 Rasero 154-4 5/63 Stevens 161190 FOREIGN PATENTS 6/57 Australia.

EARL M. BERGERT, Primary Examiner.

CARL F. KRAFFT, Examiner. 

1. AS AN ARTICLE OF MANUFACTURE, AND ENDLESS RAW EDGE V-BELT COMPRISING COMPRESSION, TENSION AND NEUTRAL AXIS SECTIONS AND LONGITUDINALLY EXTENDING STRENGTH CORDS COMPOSED OF SYNTHETIC FIBERS EMBEDDED IN SAID NEUTRAL, AXIS SECTION, THE EXPOSED FIBERS AT THE EDGES OF SAID BELT BEING PARTIALLY FUSED TO THE ADJOINING PORTION OF THE BELT. 